monitor

monitor is a skill for Claude Code, Codex from kazdenc/builder-skills. It costs 66 tokens per session (1,928 once invoked), scanned A, original, MIT.

Instructions for adding production monitoring to an application, covering errors, speed, health checks, alerts, service targets, and dashboards.

In plain words
What is it for?
Use them when setting up error tracking, performance measurements, health checks, alerts, service-level objectives, or monitoring dashboards.
Why use it?
They help teams notice failures and performance problems before users report them, while avoiding blind spots in production visibility.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/kazdenc/builder-skills/monitor
Any agent
npx skills add kazdenc/builder-skills --skill monitor
Clone the repo
git clone --depth 1 https://github.com/kazdenc/builder-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for monitor

README.md
[![agentmods](https://agentmods.dev/badge/skills/kazdenc/builder-skills/monitor.svg)](https://agentmods.dev/skills/kazdenc/builder-skills/monitor)
Your own site
<a href="https://agentmods.dev/skills/kazdenc/builder-skills/monitor"><img src="https://agentmods.dev/badge/skills/kazdenc/builder-skills/monitor.svg" alt="Measured on agentmods" height="20"></a>
Per session 66 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,928 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00066 $0.01928
Opus 5 $0.00033 $0.00964
Sonnet 5 $0.00013 $0.00386
Haiku 4.5 $0.00007 $0.00193

Measured 5d ago against content hash 7ef86a2e9a5d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

monitor scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/dev/deploy/monitor/SKILL.md · 177 lines

How it starts

The opening of the file, as written. The whole thing — 177 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Production Monitoring Setup

Set up monitoring for a production application. If a target is provided, scope recommendations to that service or feature. Cover all four pillars, then configure health checks, alerts, SLOs, and dashboards.

The Four Pillars

Monitor all four. Missing any one creates a blind spot.

1. Errors

Track unhandled exceptions, failed API calls, and client-side errors. Don't wait for users to report them.

What to capture How
Unhandled exceptions (server) Global error handler reports to error tracking service. Include stack trace and request context.
Unhandled exceptions (client) window.onerror and onunhandledrejection wired to error tracking.
Failed API calls Log 4xx and 5xx responses with request path, status, and duration.
Client-side errors React error boundaries catch render failures. Report with component tree.

Tool examples: Sentry (full stack, source maps, release tracking), LogRocket (session replay + error context).

2. Performance

Measure response times and user experience. Use percentiles, not averages.

Metric Target How to measure
API response time (p50) < 200ms Server-side timing middleware.
API response time (p95) < 500ms Same middleware, track percentile distribution.
API response time (p99) < 1000ms Same middleware. If p99 spikes, investigate outlier queries.
Largest Contentful Paint < 2.5s Real User Monitoring (RUM) or Lighthouse CI.
First Input Delay < 100ms RUM.
Cumulative Layout Shift < 0.1 RUM or Lighthouse CI.

Tool examples: Vercel Analytics (zero-config for Next.js), Speedlify (self-hosted Lighthouse tracking).

3. Availability

Know when your service is down before your users do.

What to check Frequency Alert if
Health check endpoint Every 30s Two consecutive failures.
SSL certificate expiry Daily Less than 14 days remaining.
DNS resolution Every 5m Resolution fails or returns unexpected IP.
Key third-party services Every 1m Dependency returns errors for > 2 minutes.

Read the full file on GitHub · 177 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 177 lines · 66 tokens per session scan A 7ef86a2e9a5d

Subscribe to this mod's changes

monitor is a skill published in the GitHub repository kazdenc/builder-skills (44 stars, last pushed 5mo ago), licensed MIT. It adds 66 tokens to every session and 1,928 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.